NAME

       SSL_SESSION_new, SSL_SESSION_dup, SSL_SESSION_up_ref, SSL_SESSION_free - create, free and manage
       SSL_SESSION structures

SYNOPSIS

        #include <openssl/ssl.h>

        SSL_SESSION *SSL_SESSION_new(void);
        SSL_SESSION *SSL_SESSION_dup(SSL_SESSION *src);
        int SSL_SESSION_up_ref(SSL_SESSION *ses);
        void SSL_SESSION_free(SSL_SESSION *session);

DESCRIPTION

       SSL_SESSION_new() creates a new SSL_SESSION structure and returns a pointer to it.

       SSL_SESSION_dup() copies the contents of the SSL_SESSION structure in src and returns a pointer to it.

       SSL_SESSION_up_ref() increments the reference count on the given SSL_SESSION structure.

       SSL_SESSION_free() decrements the reference count of session and removes the SSL_SESSION structure
       pointed to by session and frees up the allocated memory, if the reference count has reached 0.  If
       session is NULL nothing is done.

NOTES

       SSL_SESSION objects are allocated, when a TLS/SSL handshake operation is successfully completed.
       Depending on the settings, see SSL_CTX_set_session_cache_mode(3), the SSL_SESSION objects are internally
       referenced by the SSL_CTX and linked into its session cache. SSL objects may be using the SSL_SESSION
       object; as a session may be reused, several SSL objects may be using one SSL_SESSION object at the same
       time. It is therefore crucial to keep the reference count (usage information) correct and not delete a
       SSL_SESSION object that is still used, as this may lead to program failures due to dangling pointers.
       These failures may also appear delayed, e.g.  when an SSL_SESSION object was completely freed as the
       reference count incorrectly became 0, but it is still referenced in the internal session cache and the
       cache list is processed during a SSL_CTX_flush_sessions(3) operation.

       SSL_SESSION_free() must only be called for SSL_SESSION objects, for which the reference count was
       explicitly incremented (e.g.  by calling SSL_get1_session(), see SSL_get_session(3)) or when the
       SSL_SESSION object was generated outside a TLS handshake operation, e.g. by using d2i_SSL_SESSION(3).  It
       must not be called on other SSL_SESSION objects, as this would cause incorrect reference counts and
       therefore program failures.

RETURN VALUES

       SSL_SESSION_new returns a pointer to the newly allocated SSL_SESSION structure or NULL on error.

       SSL_SESSION_up_ref returns 1 on success or 0 on error.

SEE ALSO

       ssl(7), SSL_get_session(3), SSL_CTX_set_session_cache_mode(3), SSL_CTX_flush_sessions(3),
       d2i_SSL_SESSION(3)

HISTORY

       SSL_SESSION_dup() was added in OpenSSL 1.1.1.

COPYRIGHT

       Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the OpenSSL license (the "License").  You may not use this file except in compliance with
       the License.  You can obtain a copy in the file LICENSE in the source distribution or at
       <https://www.openssl.org/source/license.html>.